Increasing capacity in wireless communications

ABSTRACT

Techniques to increase capacity in a wireless communications system. Systematic non-transmission, or “blanking,” of minimal-rate frames transmitted in a communications system is provided. In an exemplary embodiment, eighth rate frames in a cdma2000 voice communications system are systematically substituted with null-rate frames carrying zero traffic bits. The receiver detects the presence of null rate or non-null rate transmissions and processes the received frames accordingly. Techniques for changing the pilot transmission gating pattern to assist the receiver in detecting null rate frames are provided. In another aspect, early termination of a signal transmission over a wireless communications link is provided. In an exemplary embodiment, a base station (BS) transmits power control groups (PCG&#39;s) for a frame over a forward link (FL) to a mobile station (MS) until accurate reception of the frame is acknowledged by the MS over a reverse link (RL), possibly before all PCG&#39;s of the frame are received.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 61/060,119, entitled “Apparatus and Methods for Increasing Capacityin Wireless Communications,” filed Jun. 9, 2008, and U.S. ProvisionalApplication Ser. No. 61/060,408, entitled “Apparatus and Methods forIncreasing Capacity in Wireless Communications,” filed Jun. 10, 2008,and U.S. Provisional Application Ser. No. 61/061,546, entitled“Apparatus and Methods for Increasing Capacity in WirelessCommunications,” filed Jun. 13, 2008, the contents of which are herebyincorporated by reference in their entirety.

This application is a continuation-in-part of U.S. patent applicationSer. No. 12/389,211, entitled “Frame Termination,” filed Feb. 19, 2009,which claims priority to U.S. Provisional Application No. 61/030,215,filed Feb. 20, 2008, both assigned to the assignee of the presentapplication, the contents of which are hereby incorporated by referencein their entirety.

This application is related to U.S. patent application Ser. No.12/252,544, entitled “Rate Determination,” filed Oct. 16, 2008, assignedto the assignee of the present application, the contents of which arehereby incorporated by reference in their entirety.

TECHNICAL FIELD

The present invention relates generally to digital communications, andmore specifically, to techniques for reducing transmission power andimproving the capacity of wireless digital communications systems.

BACKGROUND

Wireless communications systems are widely deployed to provide varioustypes of communication such as voice, packet data, and so on. Thesesystems may be based on code division multiple access (CDMA), timedivision multiple access (TDMA), frequency division multiple access(FDMA), or other multiple access techniques. For example, such systemscan conform to standards such as Third-Generation Partnership Project 2(3gpp2, or “cdma2000”), Third-Generation Partnership (3gpp, or“W-CDMA”), or Long Term Evolution (“LTE”). In the design of suchcommunications systems, it is desirable to maximize the capacity, or thenumber of users the system can reliably support, given the availableresources. Several factors impact the capacity of a wirelesscommunications system, some of which are described below.

For example, in a voice communications system, a vocoder is oftenemployed to encode a voice transmission using one of a plurality ofvariable encoding rates. The encoding rate may be selected based on,e.g., the amount of speech activity detected during a particular timeinterval. In a vocoder for a cdma2000 wireless communication system, forexample, speech transmissions may be sent using full rate (FR), halfrate (HR), quarter rate (QR), or eighth rate (ER) frames, with a fullrate frame containing the greatest number of traffic bits, and an eighthrate frame containing the least number of traffic bits. An eighth rateframe is usually sent during periods of silence, and generallycorresponds to the lowest-rate transmission that may be achieved by thevoice communications system.

While an eighth rate frame represents a reduced-rate transmission in acdma2000 system, the eighth rate frame still contains a non-zero numberof traffic bits. During certain intervals, e.g., relatively long periodswherein there is no speech activity and background noise remainsconstant, even the eighth rate frame transmissions may unnecessarilyconsume a significant level of transmission power in the system. Thismay raise the level of interference caused to other users, therebyundesirably decreasing system capacity.

It would be desirable to provide techniques to further decrease thetransmission rate of a voice communications system below whatminimum-rate frame transmissions such as eighth rate frame transmissionscan provide.

In another aspect of a wireless communications system, transmissionsbetween two units often employ a degree of redundancy to guard againsterrors in the received signals. For example, in a forward link (FL)transmission from a base station (BS) to a mobile station (MS) in acdma2000 wireless communications system, redundancies such asfractional-rate symbol encoding and symbol repetition may be employed.In a cdma2000 system, encoded symbols are grouped into sub-segmentsknown as power control groups (PCG's) and transmitted over the air, witha fixed number of PCG's defining a frame.

While symbol redundancy techniques such as those employed in cdma2000may allow accurate recovery of transmitted signals in the presence oferrors, such techniques also represent a premium in the overall systemtransmission power when signal reception conditions are good, which mayalso undesirably decrease the system capacity.

It would be further desirable to provide efficient techniques to, forexample, terminate transmission of a frame when it is determined thatthe receiver has accurately recovered the information associated withthat frame, thereby saving transmission power and increasing the systemcapacity. It would be further desirable to provide modified powercontrol schemes to accommodate such techniques.

SUMMARY

An aspect of the present disclosure provides a method for earlytermination of sequential frame transmissions over a communicationschannel, the method comprising: continuously transmitting a first frameto a receiver; receiving an acknowledgment message from the receiverduring the transmitting the first frame; and ceasing transmission of thefirst frame after receiving the acknowledgment message.

Another aspect of the present disclosure provides a method for earlytermination of sequential frame transmissions over a communicationschannel, the method comprising: continuously receiving a first framefrom a transmitter; attempting to decode the first frame prior toreceiving the entire first frame; determining a successful frame decodebased on a result of the attempting; and transmitting an acknowledgementmessage to the transmitter based on determining the successful framedecode, wherein the acknowledgement message is operable to ceasetransmission of the first frame.

Yet another aspect of the present disclosure provides an apparatus forearly termination of sequential frame transmissions over acommunications channel, the apparatus comprising: a transmitterconfigured to continuously transmit a first frame to a receiver; areceiver module configured to receive an acknowledgment message from thereceiver during the transmitting the first frame; and the transmitterconfigured to cease transmission of the first frame after receiving theacknowledgment message.

Yet another aspect of the present disclosure provides an apparatus forearly termination of sequential frame transmissions over acommunications channel, the apparatus comprising: a receiver configuredto continuously receive a first frame from a transmitter; a processorconfigured to: attempt to decode the first frame prior to receiving theentire first frame; determine a successful frame decode based on aresult of the attempting; and a transmitter module configured totransmit an acknowledgement message to the transmitter based ondetermining the successful frame decode, wherein the acknowledgementmessage is operable to cease transmission of the first frame.

Yet another aspect of the present disclosure provides an apparatus forearly termination of frame transmissions over a communications channel,the apparatus comprising: means for receiving from a transmitter acontinuously transmitted frame; means for terminating transmissions ofthe transmitter prior to receiving the entire frame.

Yet another aspect of the present disclosure provides an apparatus forearly termination of frame transmissions over a communications channel,the apparatus comprising: means for continuously transmitting a firstframe; means for terminating the continuously transmitting based on asuccessful decode of the at least one transmitted sub-segment by areceiver.

Yet another aspect of the present disclosure provides acomputer-readable storage medium storing instructions for causing acomputer to perform early termination of frame transmissions over acommunications channel, the medium storing instructions for causing acomputer to: receive from a transmitter a continuously transmittedframe; attempt to decode the frame prior to receiving the entirecontinuously transmitted frame; determine a successful frame decodebased on a result of the attempting; and transmit an acknowledgementmessage to the transmitter based on determining the successful framedecode, wherein the acknowledgement message is operable to terminatetransmission of a remaining portion of the continuously transmittedframe.

Yet another aspect of the present disclosure provides acomputer-readable storage medium storing instructions for causing acomputer to perform for early termination of frame transmissions over acommunications channel, each frame being allotted a fixed time intervalfor transmission, the medium storing instructions for causing a computerto: continuously transmit a first frame; receive an acknowledgmentmessage from a receiver during the transmitting the first frame; ceasetransmission of the first frame after receiving the acknowledgmentmessage; and start to transmit a second frame after the fixed timeinterval has elapsed for the first frame.

Yet another aspect of the present disclosure provides a method for earlytermination of sequential frame transmissions over a communicationschannel, the method comprising: continuously transmitting a first frameto at least one receiver; receiving at least one acknowledgment messagefrom the at least one receiver during the transmitting the first frame;and ceasing transmission of the first frame after receiving the first ofthe at least one acknowledgment message.

Yet another aspect of the present disclosure provides a method for earlytermination of sequential frame transmissions over a communicationschannel, the method comprising: continuously receiving a first framefrom at least one transmitter; attempting to decode the first frameprior to receiving the entire first frame; determining a successfulframe decode based on a result of the attempting; and transmitting anacknowledgement message based on determining the successful framedecode, wherein the acknowledgement message is operable to ceasetransmission of the first frame by each of the at least one transmitter.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a prior art wireless communications system.

FIG. 2 illustrates a prior art signal transmission path for voice.

FIG. 3 illustrates an exemplary embodiment of a signal transmission pathfor voice according to the present disclosure.

FIG. 4 illustrates an exemplary embodiment of an algorithm that may beapplied by the systematic blanking module.

FIGS. 5 and 5A illustrate exemplary frame transmission sequences asprocessed by a vocoder and a systematic blanking module.

FIG. 6 illustrates an exemplary embodiment of a receiving algorithm forprocessing systematic-blanked signals generated by a voice signaltransmission path such as shown in FIG. 3.

FIG. 7 illustrates an alternative exemplary embodiment of a signaltransmission path for voice according to the present disclosure.

FIG. 8 illustrates an exemplary embodiment of an algorithm that may beapplied by the systematic blanking module.

FIGS. 9 and 9A illustrate exemplary frame transmission sequences asprocessed by a vocoder and a systematic blanking module.

FIG. 10 illustrates an exemplary embodiment of a method for systematicblanking according to the present disclosure.

FIG. 11 illustrates an exemplary embodiment of a pilot gating schemeaccording to the present disclosure.

FIG. 12 illustrates an exemplary embodiment of a reduced rate powercontrol scheme for controlling the power of forward link (FL)transmissions according to the present disclosure.

FIG. 13 illustrates an exemplary embodiment of a reduced rate powercontrol scheme for controlling the power of reverse link (RL) continuouspilot transmissions according to the present disclosure.

FIG. 14 illustrates an exemplary embodiment of a reduced rate powercontrol scheme for controlling the power of reverse link (RL) gate pilottransmissions according to the present disclosure.

FIG. 15 illustrates a power control method according to the presentdisclosure.

FIG. 16 illustrates a prior art frame processing scheme for processinginformation bits at a transmitter in a communications system. FIG. 16Aillustrates the sequence of information bits and symbols in the frameprocessing scheme of FIG. 16.

FIG. 17 illustrates timing diagrams associated with a prior art forwardlink signaling scheme for cdma2000.

FIG. 18 illustrates a prior art method for recovering estimatedinformation bits b′ from received symbols y.

FIG. 19 illustrates an exemplary embodiment of a scheme for earlytermination of forward link transmissions for systems operatingaccording to the cdma2000 standard.

FIG. 20 illustrates an exemplary embodiment of a per-sub-segmentdecoding scheme according to the present disclosure.

FIG. 21 illustrates an implementation of a prior art forward link symbolpath for Radio Configuration 4 (RC4) according to the cdma2000 standard,as well as an exemplary embodiment of a forward link symbol pathaccording to the present disclosure.

FIG. 22 illustrates an exemplary embodiment of a signaling scheme usedto signal the ACK message on the reverse link for early terminationmodulator.

FIG. 23 illustrates an exemplary embodiment of a scheme for earlytermination of reverse link transmissions for systems operatingaccording to the cdma2000 standard.

FIG. 24 illustrates an implementation of a prior art reverse link symbolpath, as well as an exemplary embodiment of a reverse link symbol pathaccording to the present disclosure.

FIG. 25 illustrates an exemplary embodiment of a signaling scheme usedto signal the ACK message on the reverse link for early termination of aforward fundamental channel (F-FCH) and/or up to two forwardsupplemental channels (F-SCH1 and F-SCH2).

FIG. 26 illustrates an exemplary embodiment of a method according to thepresent disclosure.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of exemplary embodiments of thepresent invention and is not intended to represent the only exemplaryembodiments in which the present invention can be practiced. The term“exemplary” used throughout this description means “serving as anexample, instance, or illustration,” and should not necessarily beconstrued as preferred or advantageous over other exemplary embodiments.The detailed description includes specific details for the purpose ofproviding a thorough understanding of the exemplary embodiments of theinvention. It will be apparent to those skilled in the art that theexemplary embodiments of the invention may be practiced without thesespecific details. In some instances, well known structures and devicesare shown in block diagram form in order to avoid obscuring the noveltyof the exemplary embodiments presented herein.

In this specification and in the claims, it will be understood that whenan element is referred to as being “connected to” or “coupled to”another element, it can be directly connected or coupled to the otherelement or intervening elements may be present. In contrast, when anelement is referred to as being “directly connected to” or “directlycoupled to” another element, there are no intervening elements present.

Communications systems may use a single carrier frequency or multiplecarrier frequencies. Referring to FIG. 1, in a wireless cellularcommunications system 100, reference numerals 102A to 102G refer tocells, reference numerals 160A to 160G refer to base stations, andreference numerals 106A to 106G refer to access terminals (AT's). Acommunications channel includes a forward link (FL) (also known as adownlink) for transmissions from the access network (AN) 160 to theaccess terminal (AT) 106 and a reverse link (RL) (also known as anuplink) for transmissions from the AT 106 to the AN 160. The AT 106 isalso known as a remote station, a mobile station or a subscriberstation. The access terminal (AT) 106 may be mobile or stationary. Eachlink may incorporate a different number of carrier frequencies.Furthermore, an access terminal 106 may be any data device thatcommunicates through a wireless channel or through a wired channel, forexample using fiber optic or coaxial cables. An access terminal 106 mayfurther be any of a number of types of devices including but not limitedto PC card, compact flash, external or internal modem, or wireless orwireline phone.

Modern communications systems are designed to allow multiple users toaccess a common communications medium. Numerous multiple-accesstechniques are known in the art, such as time division multiple-access(TDMA), frequency division multiple-access (FDMA), space divisionmultiple-access, polarization division multiple-access, code divisionmultiple-access (CDMA), and other similar multi-access techniques. Themultiple-access concept is a channel allocation methodology which allowsmultiple user access to a common communications link. The channelallocations can take on various forms depending on the specificmulti-access technique. By way of example, in FDMA systems, the totalfrequency spectrum is divided into a number of smaller sub-bands andeach user is given its own sub-band to access the communications link.Alternatively, in TDMA systems, each user is given the entire frequencyspectrum during periodically recurring time slots. In CDMA systems, eachuser is given the entire frequency spectrum for all of the time butdistinguishes its transmission through the use of a code.

While certain exemplary embodiments of the present disclosure may bedescribed hereinbelow for operation according to the cdma2000 standard,one of ordinary skill in the art will appreciate that the techniques mayreadily be applied to other digital communications systems. For example,the techniques of the present disclosure may also be applied to systemsbased on the W-CDMA (or 3gpp) wireless communications standard, and/orany other communications standards. Such alternative exemplaryembodiments are contemplated to be within the scope of the presentdisclosure.

FIG. 2 illustrates a prior art signal transmission path 200 for voice.In FIG. 2, a voice signal 200 a is input to a vocoder 210, which codesthe speech signal for transmission. A voice frame 210 a output by thevocoder 210 may take on one of a plurality of rates, depending on thespeech content of the voice signal 200 a at any time. In FIG. 2, theplurality of rates includes a full rate (FR), half rate (HR), quarterrate (QR), and eighth rate (ER). The voice frame 210 a is provided to aphysical layer processing module 220, which prepares the voice framedata for transmission according to the physical layer protocols of thesystem. One of ordinary skill in the art will appreciate that suchprotocols may include, e.g., encoding, repeating, puncturing,interleaving, and/or modulating the data. The output of the physicallayer processing module 220 is provided to the TX block 230 fortransmission. The TX block 230 may perform radio-frequency (RF)operations such as upconverting the signal to a carrier frequency andamplifying the signal for transmission over an antenna (not shown).

In general, the rate of the voice frame 210 a selected by the vocoder210 to encode the voice signal 200 a at any time may depend on the levelof speech activity detected in the voice signal 200 a. For example, afull rate (FR) may be selected for frames during which the voice signal200 a contains active speech, while an eighth rate (ER) may be selectedfor frames during which the voice signal 200 a contains silence. Duringsuch periods of silence, an ER frame may contain parameterscharacterizing the “background noise” associated with the silence. Whilean ER frame contains significantly fewer bits than an FR frame, silenceperiods may occur quite often during a normal conversation, therebycausing the overall transmission bandwidth devoted to transmitting ERframes to be significant.

It would be desirable to further reduce the transmission bandwidthrequired to convey the voice signal 200 a to a receiver.

FIG. 3 illustrates an exemplary embodiment of a signal transmission path300 for voice according to the present disclosure. In FIG. 3, a voicesignal 200 a is input to a vocoder 310, which generates a voice frame310 a for transmission. The voice frame 310 a may take on one of aplurality of rates including a full rate (FR), half rate (HR), quarterrate (QR), eighth rate (ER), and a critical eighth rate (ER-C). In anexemplary embodiment, the designation of an eighth-rate frame as a“critical” eighth rate frame may be made by the vocoder 310 for thoseeighth-rate frames containing parameters corresponding to, e.g., achange in the detected background noise in the silence interval.

The voice frame 310 a is provided to a systematic blanking module 315,which in turn provides a processed voice frame 315 a to the physicallayer processing module 220. As further described hereinbelow, thesystematic blanking module 315 is configured to minimize thetransmission bitrate of the vocoder output 310 a by selectively“blanking” the vocoder output, i.e., replacing certain frames of thevocoder output 310 a with null rate (NR) frames having a data rate lessthan that of the eighth rate frame. In an exemplary embodiment, NRframes may have zero traffic content, i.e., a traffic bitrate of 0 bitsper second (bps).

FIG. 4 illustrates an exemplary embodiment 400 of an algorithm that maybe applied by the systematic blanking module 315.

At step 410, the systematic blanking module 315 receives a frame 310 afrom the vocoder 310.

At step 420, the frame 310 a is evaluated to determine whether it is FR,HR, QR, or ER-C. Such rates are deemed critical for transmission, andmay also be referred to as critical frame types. If the frame 310 acontains one of these critical rates, then the frame 310 a is directlyprovided to the physical layer processing module 220 for transmission.If not, the frame is deemed to contain a non-critical rate, and thealgorithm proceeds to step 430.

Note the exemplary designation of FR, HR, QR, and ER-C as “critical” isfor illustrative purposes only, and is not meant to restrict the scopeof the present disclosure to only those embodiments wherein such frametypes are designated as critical. In alternative exemplary embodiments,other sets of frame types may be designated critical for transmission bya systematic blanking module. Such alternative exemplary embodiments arecontemplated to be within the scope of the present disclosure.

At step 430, the algorithm evaluates a frame number of the current frameto be transmitted to determine whether the current frame is guaranteedfor transmission. In an exemplary embodiment, a guaranteed transmissionmay include a non-zero rate (e.g., non-NR) transmission. In an exemplaryembodiment, a frame number may be a number assigned to each frame thatis continuously iterated for each successive frame. In the exemplaryembodiment shown, the current frame number FrameNumber is added to thecurrent frame offset FrameOffset, and the result(FrameNumber+FrameOffset) is applied to a modulo operation (mod) with anon-blanking interval parameter N. If the result of the modulo operationis 0, the algorithm proceeds to step 440. Otherwise, the algorithmproceeds to step 450.

One of ordinary skill in the art will appreciate that techniques otherthan the specific evaluation shown at step 430 may readily be applied tospecify which frames are to be guaranteed for transmission. Suchalternative techniques may utilize, e.g., parameters other than thecurrent frame number or current frame offset, or operations other thanthe modulo operation depicted.

At step 450, the systematic blanking module 315 provides a null rate(NR) frame to the physical layer processing module 220 for transmission.In an exemplary embodiment, a null rate frame has a traffic data rate of0 bps (bits per second), and thus consumes minimal signaling bandwidth.After transmission of the null rate frame, the algorithm returns to step410 to receive the next voice frame 310 a from the vocoder 310.

Based on the above description, one of ordinary skill in the art willappreciate that the non-blanking interval N controls how oftennon-critical frames are transmitted, with N=1 corresponding totransmission of all non-critical frames, and greater values of Ncorresponding to less frequent transmissions of non-critical frames. Inan exemplary embodiment, N may take on values of 1, 4 by default, 8, orother reserved values specified, e.g., by external signaling (notshown).

FIGS. 5 and 5A illustrate exemplary frame transmission sequences 310 a*and 315 a*, respectively, as processed by a vocoder 310 and a systematicblanking module 315.

In FIG. 5, the sequence of frames 310 a* includes eighth-rate frameslabeled “ER” and eighth-rate critical frames labeled “ER-C.” Such asequence of frames may arise during a voice conversation, e.g., a periodof silence from one side of a conversation.

In FIG. 5A, the frame transmission sequence 315 a* corresponds to theresult of applying a selective blanking algorithm such as 400 to thetransmission sequence 310 a*, wherein a non-blanking interval N=4 isused. In FIG. 5A, the sequence of frames 315 a* includes eighth-rateframes ER and null-rate frames NR. FrameNum 0 is transmitted directly asreceived from vocoder 310, i.e., as an ER frame. FrameNum's 1 and 3 aretransmitted as NR frames in accordance with a non-blanking interval N=4.FrameNum 2, which is designated by the vocoder as a critical eighth-rateframe ER-C, is transmitted as an ER frame. FrameNum's 4 through 13 aresimilarly processed, as shown. Note in FIG. 5A, the frames correspondingto (FrameNum+FrameOffset mod N)=0 are marked.

FIG. 6 illustrates an exemplary embodiment of a receiving algorithm 600for processing signals generated by a voice transmission signal pathemploying a systematic blanking module such as 315 shown in FIG. 3.

In FIG. 6, at step 610, a transmitted signal is received (RX) andprocessed using, e.g., operations complementary to the TX operations 230such as shown in FIG. 3. Such RX operations may include, e.g., RFamplification, frequency downconversion, filtering, etc.

At step 620, physical layer receive (RX) processing is performed using,e.g., operations complementary to the physical layer TX operations 220shown in FIG. 3. Such physical layer receive processing may include,e.g., decoding, deinterleaving, symbol combining, etc.

At step 630, the algorithm 600 evaluates whether the current receivedframe is an NR frame. If yes, the algorithm returns to step 610 to beginreceiving the next frame, as there is no traffic data to be processedfor the NR frame. If no, the algorithm proceeds to step 640.

One of ordinary skill in the art will appreciate that various techniquesmay be employed to evaluate whether the current received frame is an NRframe. In an exemplary embodiment, an energy evaluation algorithm may beemployed to detect the energy in the traffic portion of the receivedframe. For example, the energy corresponding to the traffic portion of areceived frame may be measured, and compared to an appropriate scaledenergy threshold. If the measured energy is less than the threshold,then a NR frame may be declared, since, in an exemplary embodiment, nosignal is expected to be transmitted by the transmitter in the trafficportion of the NR frame. Such energy evaluation algorithms may alsoutilize knowledge of the systematic blanking algorithm and non-blankinginterval N used by the transmitter to further assist in the detection ofNR frames.

Note the preceding description of possible NR detection algorithms isgiven for illustrative purposes only, and is not meant to limit thescope of the present disclosure to any particular NR detectionalgorithms.

At step 640, a parameter of the received non-NR frame may be used toupdate an outer loop power control (OLPC) algorithm at the receiver. Inan exemplary embodiment, a parameter of the received non-NR frame mayinclude, e.g., the result of whether a frame quality indicator (FQI),such as a CRC for the received frame, has passed a quality check. One ofordinary skill in the art will appreciate that an OLPC algorithm may beused to, e.g., compute an appropriate signal-to-interference ratio (SIR)setpoint for received frames, which may be used to guide a power controlfeedback mechanism between the transmitter and receiver for thetransmitted voice frames. By excluding quality check results derivedfrom NR frames, the OLPC algorithm may be correctly updated using, e.g.,only frames having significant transmitted energy for the trafficportion.

At step 650, the voice frame may be decoded to a voice output 650 a, andthe algorithm 600 returns to step 610 to receive the next frame.

FIG. 7 illustrates an alternative exemplary embodiment of a signaltransmission path 700 for voice according to the present disclosure. InFIG. 7, a voice signal 200 a is input to a vocoder 710, which generatesa voice frame 710 a for transmission. The voice frame 710 a may take onone of a plurality of rates including a full rate (FR), half rate (HR),quarter rate (QR), eighth rate (ER), and a vocoder null rate (VNR). AVNR frame, also known as a zero-rate vocoder frame or empty vocoderframe, is generated by the vocoder 710 when there is no new informationto be sent by the vocoder. In an exemplary embodiment, the VNR frame maysimply be a blank frame containing no data.

The voice frame 710 a is provided to a systematic blanking module 715,which in turn provides a processed voice frame 715 a to the physicallayer processing module 220. As further described hereinbelow, thesystematic blanking module 715 is configured to minimize thetransmission bitrate of the vocoder output 710 a by selectivelyreplacing certain frames of the vocoder output 710 a with null rate (NR)or null-rate indicator (NRID) frames having little or no data content.

FIG. 8 illustrates an exemplary embodiment 800 of an algorithm that maybe applied by the systematic blanking module 715.

At step 810, the systematic blanking module 715 receives a frame 710 afrom the vocoder 710.

At step 820, the frame 710 a is evaluated to determine whether it is FR,HR, QR, or ER. Such rates are deemed critical for transmission. If theframe 710 a contains one of these critical rates, then the frame 710 ais provided to the physical layer processing module 220 for transmissionat step 840. If not, the frame is deemed to contain a non-critical rate,and the algorithm proceeds to step 830.

At step 830, the algorithm evaluates the current frame number of thetransmission to determine whether a non-zero transmission should bemade. In the exemplary embodiment shown, the current frame numberFrameNumber is added to the current frame offset FrameOffset, and theresult (FrameNumber+FrameOffset) is applied to a modulo operation (mod)with a non-blanking interval parameter N. If the result of the modulooperation is 0, the algorithm proceeds to step 835. Otherwise, thealgorithm proceeds to step 850.

At step 835, a null rate indicator (NRID) frame may be transmitted. Sucha frame may correspond to a predetermined frame or indicatorrecognizable to the receiver as containing no new information, alsoreferred to as a frame comprising null traffic data. Null traffic datamay contain a bit pattern that the receiving vocoder does not use, andthus the null traffic data will be discarded by the receiving vocoder.In one aspect, for example, the predetermined null frame or indicatormay be a known 1.8-kbps frame having null traffic data. In anotheraspect, for example, the predetermined frame or indicator may repeat thelast transmitted 1.8-kbps frame, thereby indicating null traffic data.

At step 850, the systematic blanking module 715 provides a null rate(NR) frame to the physical layer processing module 220 for transmission.In an exemplary embodiment, a null rate frame contains no traffic bits,and thus consumes minimal signaling bandwidth. After transmission of thenull rate frame, the algorithm returns to step 810 to receive the nextvoice frame 710 a from the vocoder 710.

FIGS. 9 and 9A illustrate exemplary frame transmission sequences 710 a*and 715 a*, respectively, as processed by a vocoder 710 and a systematicblanking module 715.

In FIG. 9, the sequence of frames 710 a* includes eighth-rate frameslabeled “ER” and vocoder null rate frames labeled “VNR” generated by thevocoder 710.

In FIG. 9A, the frame transmission sequence 715 a* corresponds to theresult of applying a selective blanking algorithm such as 800 to thetransmission sequence 710 a*, wherein a non-blanking interval N=4 isused. In FIG. 9A, the sequence of frames 715 a* includes eighth-rateframes ER and null-rate frames NR. FrameNum 0 is transmitted directly asreceived from the vocoder 710, i.e., as an ER frame. FrameNum's 1through 3 are transmitted as NR frames, and FrameNum 4 is transmitted asan NRID frame, in accordance with a non-blanking interval N=4. Note theNRID frame is transmitted to guarantee periodic non-zero rate frametransmission, as described with reference to the algorithm 800. Theprocessing of FrameNum's 5 through 13 may readily be understood by oneof ordinary skill in the art in light of the preceding description.

FIG. 10 illustrates an exemplary embodiment of a method 1000 forsystematic blanking according to the present disclosure. Note the method1000 is shown for illustrative purposes only, and is not meant to limitthe scope of the present disclosure to any particular method shown.

In FIG. 10, at step 1010, a determination can be made as to theexistence of new traffic information, the new traffic information to beincluded in a frame for transmission over a wireless communicationslink.

At step 1020, a decision block determines the result of thedetermination at step 1010.

At step 1030, if new traffic information exists, a traffic portioncomprising data representing the new traffic information can be added toa frame.

At step 1040, if no new traffic information exists, then no new frame istransmitted unless the respective frame corresponds to the frameguaranteed for transmission. In this case, generate the frame guaranteedfor transmission including null traffic data recognizable by thereceiving vocoder as the null data rate.

FIG. 11 illustrates an exemplary embodiment of a pilot gating scheme foridentifying null rate frame transmissions according to the presentdisclosure. Note the pilot gating scheme is given for illustrativepurposes only, and is not meant to limit the scope of the presentdisclosure to systems wherein a null rate frame transmission isnecessarily accompanied by a gated pilot transmission.

In FIG. 11, a traffic portion 1110 of a TX transmission is shown alongwith a pilot portion 1120. The pilot portion 1120 is seen to have adifferent pattern during transmission of a null rate frame than duringtransmission of a non-null rate frame. For example, as shown in FIG. 11,the pilot gating pattern for a null frame may correspond to 2sub-segments or PCG's wherein the pilot is turned on (indicated by “P”in FIG. 11), alternating with 2 sub-segments or PCG's wherein the pilotis turned off. The use of a different pilot gating pattern during nullframe transmissions may further assist a receiver in determining whethera frame currently being received is a null frame. This may be used,e.g., during null rate determination step 630 in FIG. 6.

One of ordinary skill in the art will appreciate in light of the presentdisclosure that alternative pilot gating patterns may be readily derivedto signal the presence of null frames. For example, the pilot gatingpattern may include pilot transmissions every other sub-segment or PCG,or using any other pattern. Such alternative techniques are contemplatedto be within the scope of the present disclosure.

In another aspect of the present disclosure, to further reduce thesignal transmissions of the system, the power control rate of theforward link and/or reverse link of the system may be reduced. In anexemplary embodiment, the mobile station may reduce the number offorward link power control commands it sends to the base station, suchas by only sending forward link power control commands only during PCG'scorresponding to the gated reverse link pilot transmissions, even inframes where the reverse link pilot portion is continuous (i.e.,non-gated). In another exemplary embodiment, the base station maytransmit reverse link power control commands at a reduced rate, such asin every other power control group. Further, the mobile stationreceiving these reverse link power control commands may apply each oneto control transmissions of non-null frames. For null frames, a reducednumber (e.g. less than all) of the received power control commands fromthe base station may be utilized to control the mobile station'stransmissions of null frames, such as when the reverse link pilotportion is gated, as described above. These exemplary power controltechniques are further described with reference to FIGS. 12 through 14.

FIG. 12 illustrates an exemplary embodiment 1200 of a reduced rate powercontrol scheme for controlling the power of forward link (FL)transmissions according to the present disclosure.

In FIG. 12, base station transmissions (BS TX) 1210 are shown along withmobile station transmissions (MS TX) 1220. The PCG's containing forwardlink (FL) power control (PC) commands sent by a mobile station are shownas hatched PCG's in 1220. An upward-right arrow originates from eachhatched PCG's, and points to the forward link PCG transmitted by thebase station wherein the received FL PC commands is applied. Forexample, the FL PC command sent by the mobile station in RL PCG #3 isapplied by the base station in transmitting FL PCG #4, etc.

Note in FIG. 12, the hatched PCG's in 1220 correspond to the RL PCG'swherein the RL TX pilot is turned on, according to the gated pilotscheme 1100 shown in FIG. 11. At the same time, the mobile station onlysends FL PC commands in RL PCG's corresponding to the hatched PCG's, asshown in 1220. The mobile station does not send FL PC commands in thenon-hatched RL PCG's. The FL PC commands are thus transmitted only inthose RL PCG's that are also transmitted during the gated pilot scheme,regardless of whether a gated pilot pattern is employed or not for theparticular frame (e.g., whether a particular frame is a null rate frameor not). One of ordinary skill in the art will appreciate that this mayreduce the complexity of FL PC processing, while also reducing theoverall FL PC rate.

FIG. 13 illustrates an exemplary embodiment 1300 of a reduced rate powercontrol scheme for controlling the power of reverse link (RL) continuouspilot transmissions according to the present disclosure.

In FIG. 13, the PCG's containing reverse link (RL) power control (PC)commands sent by a base station are shown as hatched PCG's in 1310. Adownward-right arrow originates from each hatched PCG, and points to thereverse link PCG transmitted by the mobile station that applies thecorresponding received RL PC commands. For example, the RL PC commandsent by the base station in FL PCG #3 is applied by the mobile stationin transmitting RL PCG #4, etc.

In FIG. 13, the base station only sends RL PC commands in FL PCG'scorresponding to the hatched PCG's, as shown in 1310. The base stationdoes not send RL PC commands in the non-hatched PCG's.

FIG. 14 illustrates an exemplary embodiment 1400 of a reduced rate powercontrol scheme for controlling the power of reverse link (RL) gatedpilot transmissions according to the present disclosure.

In FIG. 14, the PCG's containing forward link (RL) power control (PC)commands sent by a base station are again shown as hatched PCG's in1410. A solid downward-right arrow originates from a hatched PCG, andpoints to the reverse link PCG transmitted by the mobile station thatapplies the corresponding received RL PC commands. On the other hand, adashed arrow originating from a hatched PCG indicates an RL PC commandtransmitted by the base station that is not applied by the MS to thecorresponding RL PCG pointed to. The base station only sends RL PCcommands in FL PCG's corresponding to the hatched PCG's. The basestation does not send RL PC commands in the non-hatched PCG's.

For example, the RL PC command sent by the base station in FL PCG #1 isapplied by the mobile station in transmitting RL PCG #3, etc. On theother hand, the RL PC command sent by the base station in FL PCG #2 isnot applied by the mobile station in transmitting RL PCG #4. Instead, inan exemplary embodiment, the mobile station can maintain the same powerlevel as used for the previous PCG, e.g., RL PCG #3 in the exampledescribed. In an aspect of the present disclosure, this may be done tosimplify the processing of RL PC commands by the mobile station.

FIG. 15 illustrates a power control method 1500 according to the presentdisclosure. Note the method 1500 is shown for illustrative purposesonly, and is not meant to limit the scope of the present disclosure.

At step 1510, a current frame is received, the frame being formattedinto a plurality of sub-segments.

At step 1520, the received frame is processed according to physicallayer protocols.

At step 1530, a power control command received in a sub-segmentdesignated for transmission according to a first gated pilot pattern isreceived.

At step 1540, the transmission power of a TX sub-segment following thedesignated sub-segment is adjusted according to the received powercontrol command, the TX sub-segment being transmitted according to asecond gate pilot pattern.

According to another aspect of the present disclosure, techniques areprovided for early termination of forward and/or reverse linktransmissions in a wireless communications system to save power andincrease capacity.

FIG. 16 illustrates a prior art frame processing scheme for processinginformation bits 1600 b at a transmitter in a communications system. Incertain exemplary embodiments, the frame processing scheme shown may beutilized in the forward link or reverse link transmissions of a wirelesscommunications system. FIG. 16A illustrates the status of the dataprocessed by the operations illustrated in FIG. 16.

Note the frame processing scheme is shown for illustrative purposesonly, and is not meant to restrict the scope of the present disclosureto any particular processing scheme shown. Alternative exemplaryembodiments of the present disclosure may adopt alternative frameprocessing schemes which may, e.g., re-order the steps of the schemeshown in FIG. 16, and/or add steps to or delete steps from the schemeshown. Such alternative exemplary embodiments are contemplated to bewithin the scope of the present disclosure.

In FIG. 16, an information source generates information bits 1600 b at aselected rate R. The number of information bits 1600 b generated perframe may depend on the selected rate R. For example, in a cdma2000system, there may be 172 information bits per 20-millisecond frame(“full rate”), 80 bits per frame (“half rate”), 40 bits per frame(“quarter rate”), or 16 bits per frame (“eighth rate”). The informationbits 1600 b for a frame are collectively denoted by the variable b inFIG. 16A.

At step 1600, a frame-quality indicator (FQI) may be generated andappended to the information bits 1600 b for a frame. For example, an FQImay be a cyclical-redundancy check (CRC) known to one of ordinary skillin the art. Signal 1600 a represents the combination of the informationbits 1600 b and the FQI, as also illustrated in FIG. 16A.

At step 1610, encoder tail bits may be added to the signal 1600 a. Forexample, encoder tail bits may represent a fixed number of zero-valuedtail bits for use with a convolutional encoder. Signal 1610 a representsthe combination of signal 1600 a with the encoder tail bits, as alsoillustrated in FIG. 16A.

At step 1620, the signal 1610 a is encoded and repeated (or punctured).As earlier described, the encoding may include convolutional encoding orturbo encoding, and the repetition may serve to further increase (ordecrease, in the case of puncturing) the transmitted energy associatedwith each symbol. Note the encoding may employ other techniques known toone of ordinary skill in the art, such as block encoding or other typesof encoding, and need not be limited to the encoding explicitlydescribed in the present disclosure. The signal 1620 a represents theencoded and repeated (or punctured) version of signal 1610 a, as alsoillustrated in FIG. 16A.

At step 1630, the signal 1620 a is interleaved, e.g., to improve thediversity of the encoded symbols along a chosen signal dimension. In anexemplary implementation, the symbols may be interleaved over time.Signal 1630 a represents the interleaved version of signal 1620 a, asalso illustrated in FIG. 16A.

At step 1640, the interleaved symbols of signal 1630 a are mapped to apre-defined frame format, as also illustrated in FIG. 16A. A frameformat may specify the frame as being composed of a plurality ofsub-segments. In an exemplary embodiment, sub-segments may be anyportions of the frame contiguous along a given dimension, e.g., time,frequency, code, or any other dimension. A frame may be composed of afixed plurality of such sub-segments, each sub-segment containing aportion of the total number of symbols allocated to the frame. Forexample, in an exemplary embodiment according to the W-CDMA standard, asub-segment may be defined as a slot. In an exemplary embodimentaccording to the cdma2000 standard, a sub-segment may be defined as apower control group (PCG).

In certain exemplary embodiments, the interleaved symbols may be mappedin time, frequency, code, or any other dimensions used for signaltransmission. Furthermore, a frame format may also specify the inclusionof, e.g., control symbols (not shown) along with the interleaved symbolsof signal 1630 a. Such control symbols may include, e.g., power controlsymbols, frame format information symbols, etc. Signal 1640 a representsthe output of the symbol-to-frame mapping step 1640, as also illustratedin FIG. 16A.

At step 1650, the signal 1640 a is modulated, e.g., onto one or morecarrier waveforms. In certain exemplary embodiments, the modulation mayemploy, e.g., QAM (quadrature amplitude modulation), QPSK (quadraturephase-shift keying), etc. Signal 1650 a represents the modulated versionof the signal 1640 a, as also illustrated in FIG. 16A. Signal 1650 a isfurther denoted by the variable x in FIG. 16A.

At step 1660, the modulated signal 1650 a is further processed,transmitted over the air, and received by a receiver. Step 1660generates the received symbols 1700 a, further denoted by the variable yin FIG. 16A. Note one of ordinary skill in the art will appreciate thatthe techniques for processing the signal 1650 a for transmission andreception over-the-air are well-known, and are not further disclosedherein. The symbols contained in y may be further processed as describedhereinbelow.

FIG. 17 illustrates timing diagrams associated with a prior art forwardlink signaling scheme for cdma2000.

In FIG. 17, the base station (BS) transmits at 1700 a series of frameson a forward fundamental channel (F-FCH TX) to the mobile station (MS).In the exemplary embodiment shown, the sub-segments correspond to powercontrol groups (PCG's), sixteen (numbered 0 to 15) of which make up eachframe. Upon transmitting all sixteen PCG's corresponding to a firstframe TX Frame #0, the BS begins transmitting the next frame TX Frame#1. In an exemplary embodiment, the data transmitted may be processed aspreviously described herein with reference to FIGS. 16 and 16A.

On the MS side, the MS receives at 1710 the PCG's transmitted. Uponreceiving the last PCG (i.e., PCG #15) of RX Frame #0 corresponding toTX Frame #0, the MS begins decoding RX Frame #0 using all PCG'sreceived. The decoded information is available a decoding time TDthereafter. In an exemplary embodiment, the decoding may be performed asdescribed hereinbelow with reference to FIG. 18. Note while the MS isdecoding TX Frame #0, the PCG's of TX Frame #1 are simultaneouslyreceived.

FIG. 18 illustrates a prior art method 1800 for recovering estimatedinformation bits b′ from received symbols y.

At step 1805, symbols y or 1700 a are received for an entire frame.

At step 1810, the symbols y or 1700 a are demodulated, parsed, anddeinterleaved to produce symbols y′, also denoted as signal 1810 a. Oneof ordinary skill in the art will appreciate that the operationsperformed at step 1810 may correspond to an inverse of the operationsperformed at the transmitter, as shown in, e.g., FIG. 16.

At step 1820, the symbols y′ are decoded and combined, given knowledgeof the rate R. In an implementation, the rate R may indicate how manybits are present in a received frame, and may be used, e.g., by thedecoder to determine at which point in the received symbol sequence toterminate decoding, and/or remove tail bits from the decoded sequence.At step 1820, tail bits of the decoded sequence, e.g., as appended atstep 1610 of FIG. 16, may also be removed. The result of step 1820 is anoutput signal 1820 a.

At step 1830, the FQI, e.g., as appended at step 1600 of FIG. 16, ischecked, and also removed from the information bits. In animplementation, the result of the FQI check may identify the decoding aseither a success or a failure. Step 1830 generates the recoveredinformation bits, denoted as b′, along with the FQI result, which mayindicate either a success or failure.

At step 1840, the method may proceed to the next frame, and repeat thesteps described above for the next frame.

In accordance with the present disclosure, early frame decoding andtermination techniques as described hereinbelow may allow the overallcommunications system 100 to operate more efficiently and savetransmission power, thereby increasing cellular capacity.

FIG. 19 illustrates an exemplary embodiment of a scheme for earlytermination of forward link transmissions for systems operatingaccording to the cdma2000 standard. Note the exemplary embodiment isshown for illustrative purposes only, and is not meant to limit thescope of the present disclosure to systems based on cdma2000. One ofordinary skill in the art will also appreciate that specific PCG andframe numbers referred to herein are for illustrative purposes only, andare not meant to limit the scope of the present disclosure.

In FIG. 19, the base station (BS) transmits a series of frames at 1900to the mobile station (MS). In an exemplary embodiment, thetransmissions may be done on a fundamental forward channel (F-FCH TX).As described earlier hereinabove, each sub-segment shown in FIG. 19 maycorrespond to a power control group (PCG) in cdma2000. The BS commencestransmission with PCG #0 of TX Frame #0, and continuously transmitsPCG's until an ACK signal 1945 is received from the MS after PCG #8. TheACK signal is transmitted by the MS to signal to the BS that the MS hassuccessfully decoded the entire TX Frame #0 based on the PCG's alreadyreceived.

Upon receiving the ACK 1945, the BS ceases transmission of PCG'scorresponding to TX Frame #0, and waits until the beginning of the nextframe, TX Frame #1, before transmitting PCG's for the new frame TX Frame#1. Note during the finite period of time associated with receiving andprocessing the ACK signal 1945, the BS may already have beguntransmitting PCG #9 of TX Frame #0.

Reference numerals 1910 through 1940 illustrate the timing of actionstaken by the MS to generate the ACK signal 1945 sent to the BS thatallows early termination of TX frame transmissions by the BS.

At 1910, the MS receives the PCG's for TX Frame #0 and TX Frame #1 as RXFrame #0 and RX Frame #1, respectively.

At 1920, the MS attempts to decode RX Frame #0 as each PCG of RX Frame#0 is received, without waiting for all sixteen PCG's allocated to RXFrame #0 to be received. In an exemplary embodiment, to accomplish suchdecoding on a per-PCG basis, the MS may utilize a per-sub-segmentdecoding algorithm such as 2000 later described hereinbelow withreference to FIG. 20.

At 1925, after receiving PCG #7, the MS successfully decodes RX Frame#0, as determined by, e.g., checking the CRC associated with thereceived bits. The MS declares a decoding success, and proceeds to theACK transmission 1930.

At 1930, after declaring decoding success at 1925, the MS transmits anMS ACK signal 1945 to the BS during a portion of the transmissionassociated with PCG #8 of the reverse link.

In an exemplary embodiment, the MS may simply transmit the ACK signalduring the PCG immediately subsequent to, or at any PCG subsequent to,the PCG in which a decoding success is determined. In an alternativeexemplary embodiment such as that shown in FIG. 19, the timing of theACK signal 1945 transmission may be controlled by an ACK mask 1940. TheACK mask is operable to specify when an ACK signal may or may not betransmitted. Providing such an ACK mask may limit the communicationslink capacity utilized by the sending of acknowledgement messages.

In FIG. 19, the ACK mask 1940 is characterized by time intervalsdesignated “1” during which ACK transmission on the reverse link isallowed. ACK transmissions are not allowed during time intervalsdesignated “0.” In an exemplary embodiment, by restricting ACKtransmissions to only time intervals after a threshold PCG, the ACK maskmay ensure that decoding is only attempted when a sufficient portion ofthe received frame has been processed. According to the presentdisclosure, the MS may transmit an ACK message in the next time perioddesignated as “1” by an ACK mask that immediately follows a successfuldecode.

Note the particular ACK mask configurations shown herein are forillustrative purposes only, and are not meant to restrict the scope ofthe present disclosure to any ACK mask shown. One of ordinary skill inthe art will appreciate that alternative ACK mask configurations mayreadily be provided to allow ACK transmission during different portionsof the sub-segments or PCG's than those shown. Such alternativeexemplary embodiments are contemplated to be within the scope of thepresent disclosure.

In an exemplary embodiment, the PCG's designated by the ACK mask patternmay overlap with the same PCG's as prescribed by a pattern for an RLgated pilot pattern used to signal an NR frame transmission, such asearlier described herein with reference to FIG. 11.

In an exemplary embodiment, the BS TX may also include a pilottransmission (not shown) that may switch from a continuously transmittedpilot signal to a gated pilot signal upon receiving the MS ACK 1945, thegated pilot signal being transmitted according to a gated pilot pattern.

FIG. 20 illustrates an exemplary embodiment of a per-sub-segmentdecoding scheme according to the present disclosure. Note the method2000 is shown for illustrative purposes only, and is not intended torestrict the scope of the present disclosure to any particular exemplaryembodiments shown.

In FIG. 20, at step 2001, a sub-segment index n is initialized to n=0.

At step 2005, the method receives symbols y_(n) for sub-segment n.

At step 2010, the method demodulates, parses, and deinterleaves allsymbols y_(n) received up to and including sub-segment n of the currentframe. y_(n) may include, e.g., all traffic symbols received fromsub-segment 0 through sub-segment n, inclusive. The result of step 2010is denoted as y′_(n).

At step 2020, the method decodes and combines the symbols y′_(n). One ofordinary skill in the art will appreciate that while the symbols y′_(n)in general correspond to only a portion of the total symbols x allocatedby the transmitter for the entire frame, “early” decoding of the entireframe using only the symbols y′_(n) may nevertheless be attempted. Suchan early decoding attempt may have a good chance of decoding success dueto, e.g., redundancy in the symbols x introduced by fractional rateencoding and/or repetition, e.g., at step 1620 of FIG. 16, and/or time-or other-dimensional diversity achieved via interleaving at step 1630 ofFIG. 16.

At step 2020, the encoded tail bits may further be removed from thedecoded bit sequence to generate the signal 2020 a.

At step 2030, the method checks the FQI from the signal 2020 a, andgenerates an FQI result 2030 a from the accumulated receivedsub-segments for the current frame up to n.

At step 2035, the method evaluates whether the FQI result indicated asuccess. If yes, the method proceeds to step 2040, wherein decoding isdeclared successful, and the method proceeds to ACK message generationto enable early termination of forward link transmissions. The nextavailable opportunity may be, e.g., as specified by an ACK mask asdescribed with reference to FIG. 5. If no, the method proceeds to step2037.

At step 2037, the method increments n, and determines whether there areadditional sub-segments left in the frame to be received. If yes, themethod returns to step 2005. If no, the method proceeds to declaredecoding for the frame unsuccessful at step 2060.

At step 2070, the decoder proceeds to evaluate the next frame.

FIG. 21 illustrates an implementation 2100 of a prior art forward linksymbol path for Radio Configuration 4 (RC4) according to the cdma2000standard, as well as an exemplary embodiment 2110 of a forward linksymbol path according to the present disclosure. In the implementation2100, the frame quality indicator includes CRC's of length 6, 6, 8, or12 that are appended to the bits of a frame, depending on the framesymbol rate. In the exemplary embodiment 2110 according to the presentdisclosure, the frame quality indicator includes CRC's of increasedlength 12, 12, 12, or 12 that are appended to the bits of a frame. Theuse of increased-length CRC's improves the performance of the earlydecoding schemes according to the present disclosure, allowing, e.g.,more accurate detection of decoding success for early decodingtechniques according to the present disclosure. Note the specific CRClengths illustrated herein are provided for illustrative purposes only,and are not meant to limit the scope of the present disclosure to anyparticular CRC lengths illustrated.

As further shown in the implementation 2100, the symbol puncture ratesare 1/5, 1/9, None, and None, depending on the frame symbol rate. In theexemplary embodiment 2110 according to the present disclosure, thesymbol puncture rates are 1/3, 1/5, 1/25, and None, depending on theframe symbol rate. One of ordinary skill in the art will appreciate thatthe increased puncturing in the exemplary embodiment 2110 may be used toaccommodate the increased length CRC's called for by the exemplaryembodiment 2110.

FIG. 22 illustrates an exemplary embodiment of a signaling scheme 2200used to signal the ACK message on the reverse link for early terminationof forward link transmissions. In FIG. 22, a reverse ACK channel(R-ACKCH) 2210 is modulated using on-off keying (OOK) onto a Walsh codeW(64, 16) 2212 using modulator 2214. A relative channel gain 2216 isapplied to the resultant signal, and provided to the additive combiner2218.

In FIG. 22, a reverse fundamental channel (R-FCH) 2220 having a rate of1536 symbols per 20 ms is modulated onto a Walsh function W(16,4) 2222using a modulator 2224. A relative channel gain 2226 is applied to theresultant signal, and the result also provided to the additive combiner2218. The output of the additive combiner may be provided on aquadrature (Q) channel 2228 for reverse link transmission to the BS. Inthe exemplary embodiment shown, an in-phase (I) channel 2234 is alsoprovided that includes a reverse pilot channel (R-PICH) 2230.

Note the exemplary embodiment of the reverse link ACK signaling schemeshown with reference to FIG. 22 is given for illustrative purposes only,and is not meant to limit the scope of the present disclosure to anyparticular embodiment of an ACK signaling scheme. One of ordinary skillin the art will appreciate that alternative techniques for signaling anACK on the reverse link may be readily derived in light of the presentdisclosure, including applying different forms of modulation, andsending the ACK message on alternative channels than shown. Suchalternative exemplary embodiments are contemplated to be within thescope of the present disclosure.

FIG. 23 illustrates an exemplary embodiment of a scheme 2300 for earlytermination of reverse link transmissions for systems operatingaccording to the cdma2000 standard. Note the exemplary embodiment isshown for illustrative purposes only, and is not meant to restrict thescope of the present disclosure to any particular reverse link earlytermination scheme shown. One of ordinary skill in the art willappreciate that the specific PCG and Frame numbers referred to hereinare for illustrative purposes only.

In FIG. 23, the mobile station (MS) transmits a series of frames at 2300to the base station (BS). In an exemplary embodiment, the frames may betransmitted on a reverse fundamental channel (R-FCH TX). In FIG. 23,each sub-segment shown corresponds to a power control group (PCG). TheMS commences transmission of TX Frame #0 at PCG #0, and continuouslytransmits PCG's until an ACK signal 2345 is received from the BS afterPCG #8. Upon receiving the ACK 2345, the MS ceases transmission of PCG'scorresponding to TX Frame #0, and waits until the beginning of the nextframe, TX Frame #1, to begin transmitting PCG's corresponding to TXFrame #1.

Reference numerals 2310 through 2340 illustrate the timing of actionstaken by the BS to generate the ACK signal 2345 sent to the MS thatallows early termination of reverse link frame transmissions by the MS.

At 2310, the BS receives the PCG's of TX Frame #0 and TX Frame #1 as RXFrame #0 and RX Frame #1, respectively.

At 2320, the BS attempts to decode RX Frame #0 as each individual PCG isreceived, without waiting for all sixteen PCG's allocated to RX Frame #0to be received. In an exemplary embodiment, to accomplish such decodingon a per-PCG basis, the BS may utilize a per-sub-segment decodingalgorithm such as 2000 earlier described with reference to FIG. 20.

At 2325, after receiving PCG #5, the BS declares a decoding success, andproceeds to the ACK transmission step 2330 to generate the BS ACK TXsignal.

At 2330, after declaring decoding success at step 2325, the BS transmitsan ACK signal 2345 during a portion of the transmission associated withPCG #8 of the Forward Link. The portion of the transmission during whichan ACK signal 2345 is sent may be defined by a corresponding ACK mask2340.

In an exemplary embodiment, the ACK mask pattern may allow ACKtransmission only during those PCG's in which a power control command issent on the forward link (FL) to control reverse link (RL) powertransmissions, as earlier described herein with reference to FIG. 19.

In FIG. 23, 2350 further illustrates the transmission of the reverselink pilot signal by the MS according to the exemplary embodiment of thereverse link early termination scheme. At step 2350, after the ACKsignal 2345 is received by the MS from the BS at PCG #8, the MS ceasestransmitting the RL pilot signal at every PCG. Rather, as shown, the RLpilot signal transmission may be gated OFF for select PCG's. This mayserve to both conserve RL pilot signal transmission power for theremaining PCG's, as well as to provide an additional ACK signalingmechanism to the BS. In an exemplary embodiment, the RL gated pilotpattern for the remaining PCG's may correspond to a pattern used tosignal an NR frame transmission, such as earlier described herein withreference to FIG. 11.

In the exemplary embodiment shown, the RL pilot signal is gated OFFduring PCG's 9, 10, 13, and 14. In general, the RL pilot signal may begated OFF in alternating groups of two PCG's after the ACK signal istransmitted, until the end of the early terminated frame. It shouldfurther be noted that, as with pilot gating of NR frames, variousschemes may be utilized for the pilot gating of early terminated frames,such as: one power control group on followed by one power control groupoff; two power control groups on followed by two power control groupsoff, and any other pattern operable to reduce transmission power.

FIG. 24 illustrates an implementation 2400 of a prior art reverse linksymbol path, as well as an exemplary embodiment 2410 of a reverse linksymbol path according to the present disclosure. In the implementation2400, CRC's of length 6, 6, 8, or 12 are appended to the bits of aframe, depending on the frame symbol rate. In the exemplary embodiment2410 according to the present disclosure, CRC's of increased length 12,12, 12, or 12 may be appended to the bits of a frame. As in the case ofthe forward link processing illustrated in FIG. 21, the use ofincreased-length CRC's improves the performance of the early decodingschemes according to the present disclosure, allowing, e.g., moreaccurate detection of decoding success for the early decodingtechniques. Note the specific CRC lengths illustrated herein areprovided for illustrative purposes only, and are not meant to limit thescope of the present disclosure to any particular CRC lengthsillustrated.

As further shown in the implementation 2400, the symbol puncture ratesare 1/5, 1/9, None, and None, depending on the frame symbol rate. In theexemplary embodiment 2410 according to the present disclosure, thesymbol puncture rates are 1/3, 1/5, 1/25, and None, depending on theframe symbol rate. One of ordinary skill in the art will appreciate thatthe increased use of puncturing in the exemplary embodiment 2410 mayaccommodate the increased length CRC's that are also present in theexemplary embodiment 2410.

In an exemplary embodiment, the ACK signal sent by the BS to the MS maybe provided by supplanting (puncturing) a bit having a predeterminedposition on a forward link traffic channel, and/or using on-off keying(OOK) at the predetermined position to signal an ACK or NAK (noacknowledgment) to the MS. In an exemplary embodiment, the predeterminedposition may be varied on a per-frame basis according to a predeterminedpseudorandom bit pattern. In an exemplary embodiment, the ACK bit may betime domain multiplexed (TDM'ed) with a reverse link power control bit.

Note the frame early termination aspects described above may be appliednot only to a fundamental channel of a cdma2000 communications link, butalso to a “high data rate” supplemental channel. For example, in analternative exemplary embodiment (not shown), an ACK signaling mechanismon the forward link may be used to enable early termination oftransmissions by one or more MS's on one or more corresponding reversesupplemental channels.

For example, in an exemplary embodiment (not shown), one or more MS'smay simultaneously transmit frames on corresponding reverse supplementalchannels. If the BS successfully receives a frame on a reversesupplemental channel from an MS, the BS may transmit an ACK on acorresponding forward common acknowledgment subchannel of a forwardcommon acknowledgment channel, with one subchannel of each forwardcommon acknowledgment channel assigned to control one reversesupplemental channel. In this manner, forward common acknowledgmentsubchannels from multiple MS's may be multiplexed on a single forwardcommon acknowledgment channel. For example, in an exemplary embodiment,multiple subchannels may be time multiplexed on a single commonacknowledgment channel according to a predetermined pattern known to theBS and the one or more MS's. Such predetermined pattern may be indicatedvia external signaling (not shown).

The BS may support operation on one or more forward commonacknowledgment channels. In an exemplary embodiment, the sub-segments orPCG's in which the forward common acknowledgment channel for the reversesupplemental channels can be transmitted may be indicated by an ACK maskas previously described herein.

In an alternative exemplary embodiment, an ACK signaling mechanism onthe reverse link may be provided to control transmissions on both aforward fundamental channel and one or more forward supplementalchannels, for systems operating according to the cdma2000 standard. FIG.25 illustrates an exemplary embodiment of a signaling scheme 2500 usedto signal the ACK message on the reverse link for early termination of aforward fundamental channel (F-FCH) and/or up to two forwardsupplemental channels (F-SCH1 and F-SCH2).

In FIG. 25, a reverse ACK channel (R-ACKCH) 2520 is modulated usingbinary phase shift keying (BPSK) onto a Walsh function W(64, 16) 2522using modulator 2524. In an exemplary embodiment, the R-ACKCH 2520 maysignal the BS to terminate transmissions on a forward fundamentalchannel (F-FCH). A relative channel gain 2526 is applied to theresultant signal, and provided to the additive combiner 2518.

In FIG. 25, a second reverse ACK channel (R-ACKCH) 2510 is modulatedusing binary phase shift keying (BPSK) onto a Walsh function W(16, 12)2512 using modulator 2514. In an exemplary embodiment, the ACKCH 2510may signal the BS to terminate transmissions on a first forwardsupplemental channel (F-SCH1). A relative channel gain 2516 is appliedto the resultant signal, and provided to the additive combiner 2518.

As further shown in FIG. 25, both the R-ACK channels may be combinedwith a reverse fundamental channel (R-FCH) onto the quadrature (Q)component of the RL signal. The R-FCH may have a rate of 1536 symbolsper 20 ms, and is also modulated onto a Walsh function W(16,4) 2532using a modulator 2534. A relative channel gain 2536 is applied to theresultant signal, and provided to the additive combiner 2518. The outputof the additive combiner may be provided on a quadrature (Q) channel2528 for reverse link transmission to the BS.

As further shown in FIG. 25, a third reverse ACK channel (R-ACKCH) 2550is modulated using on-off keying (OOK) onto a Walsh function W(16, 8)2552 using modulator 2554. In an exemplary embodiment, the ACKCH 2550may signal the BS to terminate transmissions on a second forwardsupplemental channel (F-SCH2). A relative channel gain 2556 is appliedto the resultant signal, and provided to the additive combiner 2548.R-ACKCH 2550 may be combined with a reverse pilot channel (R-PICH) 2540using adder 2548 to generate the in-phase (I) reverse link signal 2544.

One of ordinary skill in the art will appreciate that the aboveillustrations of specific ACK signaling schemes for the forward link aregiven for illustrative purposes only, and are not meant to limit thescope of the present disclosure to any particular ACK signaling schemesfor the forward and reverse channels.

FIG. 26 illustrates an exemplary embodiment of a method 2600 accordingto the present disclosure. Note the method 2600 is shown forillustrative purposes only, and is not meant to restrict the scope ofthe present disclosure to any particular method.

At step 2610, a voice frame is received.

At step 2620, the method attempts early decoding of the voice framereceived. In an exemplary embodiment, the early decoding may beattempted prior to all sub-segments of the frame being received.

At step 2630, the method determines whether the attempted voice framedecoding has been successful. In an exemplary embodiment, a framequality indicator such as a CRC may be checked to determine whetherframe decoding has been successful.

At step 2640, an acknowledgment signal (ACK) is transmitted to terminatevoice frame transmission.

The early termination techniques of the present disclosure may readilybe applied to situations wherein a mobile station is in “soft handoff,”i.e., wherein an MS communicates simultaneously with multiple BS's onthe forward and/or reverse link.

For example, when an MS is in soft handoff between two BS's, the reverselink transmissions by the MS may be received at each of the two BS's,either or both of which may transmit an ACK signal (not necessarily atthe same time) back to the MS to cease MS transmissions. In an exemplaryembodiment, in response to receiving more than one ACK signal over thecourse of a reverse link frame transmission, the MS may ceasetransmission of the current frame after receiving the first of the ACKsignals. Furthermore, early termination may be similarly applied tocontrol forward link transmissions by the two BS's to an MS. Forexample, in response to successful early decoding of a frame receivedsimultaneously from two BS's, an MS may transmit an ACK signal to ceasetransmissions by both BS's on the forward link. Such alternativeexemplary embodiments are contemplated to be within the scope of thepresent disclosure.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the exemplary embodiments disclosed herein may beimplemented as electronic hardware, computer software, or combinationsof both. To clearly illustrate this interchangeability of hardware andsoftware, various illustrative components, blocks, modules, circuits,and steps have been described above generally in terms of theirfunctionality. Whether such functionality is implemented as hardware orsoftware depends upon the particular application and design constraintsimposed on the overall system. Skilled artisans may implement thedescribed functionality in varying ways for each particular application,but such implementation decisions should not be interpreted as causing adeparture from the scope of the exemplary embodiments of the invention.

The various illustrative logical blocks, modules, and circuits describedin connection with the exemplary embodiments disclosed herein may beimplemented or performed with a general purpose processor, a DigitalSignal Processor (DSP), an Application Specific Integrated Circuit(ASIC), a Field Programmable Gate Array (FPGA) or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general purpose processor may be a microprocessor,but in the alternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described in connection with theexemplary embodiments disclosed herein may be embodied directly inhardware, in a software module executed by a processor, or in acombination of the two. A software module may reside in Random AccessMemory (RAM), flash memory, Read Only Memory (ROM), ElectricallyProgrammable ROM (EPROM), Electrically Erasable Programmable ROM(EEPROM), registers, hard disk, a removable disk, a CD-ROM, or any otherform of storage medium known in the art. An exemplary storage medium iscoupled to the processor such that the processor can read informationfrom, and write information to, the storage medium. In the alternative,the storage medium may be integral to the processor. The processor andthe storage medium may reside in an ASIC. The ASIC may reside in a userterminal. In the alternative, the processor and the storage medium mayreside as discrete components in a user terminal.

In one or more exemplary embodiments, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by acomputer. By way of example, and not limitation, such computer-readablemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage or other magnetic storage devices, or anyother medium that can be used to carry or store desired program code inthe form of instructions or data structures and that can be accessed bya computer. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and Blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

The previous description of the disclosed exemplary embodiments isprovided to enable any person skilled in the art to make or use thepresent invention. Various modifications to these exemplary embodimentswill be readily apparent to those skilled in the art, and the genericprinciples defined herein may be applied to other exemplary embodimentswithout departing from the spirit or scope of the invention. Thus, thepresent invention is not intended to be limited to the exemplaryembodiments shown herein but is to be accorded the widest scopeconsistent with the principles and novel features disclosed herein.

The invention claimed is:
 1. A method for early termination ofsequential frame transmissions over a communications channel, the methodcomprising: commencing transmission of a first frame to a receiver, eachframe formatted into a plurality of sequential sub-segments andsequentially transmitted without awaiting sub-segment acknowledgmentuntil a successful decode of the first frame; receiving anacknowledgment message from the receiver during the transmission of thefirst frame, the acknowledgment message transmitted at one ofpredetermined times designated by an acknowledgement mask designating aninterval having a duration of less than a complete one of the pluralityof sequential sub-segments and indicating a successful decode of thefirst frame based on an already transmitted portion of the plurality ofsequential sub-segments of the first frame; and ceasing the transmissionof an untransmitted portion of the plurality of sequential sub-segmentsof the first frame after receiving the acknowledgment message.
 2. Themethod of claim 1, each frame allotted a fixed time interval fortransmission, further comprising: commencing transmission of a secondframe after the fixed time interval has elapsed for the first frame, thesecond frame immediately following the first frame in frame sequence. 3.The method of claim 1, further comprising adjusting a transmit power ofthe first frame in response to receiving a power control message fromthe receiver.
 4. The method of claim 1, the commencing transmissioncomprising: continuously transmitting sub-segments of the first frame insequence to the receiver.
 5. The method of claim 1, each framecomprising fractionally encoded bits interleaved over time.
 6. A methodfor early termination of sequential frame transmissions over acommunications channel, the method comprising: commencing reception of afirst frame from a transmitter, each frame formatted into a plurality ofsequential sub-segments and sequentially received without awaitingsub-segment acknowledgment until a successful decode of the first frame;attempting to decode the first frame prior to receiving the entire firstframe; determining a successful frame decode based on a result of theattempting; and transmitting an acknowledgment message to thetransmitter based on determining the successful frame decode, theacknowledgment message transmitted at one of predetermined timesdesignated by an acknowledgement mask designating an interval having aduration of less than a complete one of the plurality of sequentialsub-segments and indicating a successful decode of the first frame basedon an already transmitted portion of the plurality of sequentialsub-segments of the first frame, wherein the acknowledgment messagecauses the transmitter to cease transmission of an untransmitted portionof the plurality of sequential sub-segments of the first frame.
 7. Themethod of claim 6, each frame allotted a fixed time interval fortransmission, further comprising: commencing reception a second frameafter the fixed time interval has elapsed for the first frame, thesecond frame immediately following the first frame in frame sequence. 8.The method of claim 6, further comprising transmitting a power controlmessage to the transmitter to adjust a transmit power of the firstframe.
 9. The method of claim 6, the commencing reception comprising:continuously receiving sub-segments of the first frame in sequence fromthe transmitter.
 10. The method of claim 6, wherein transmitting theacknowledgment message further comprises transmitting only at the one ofthe predetermined times.
 11. The method of claim 6, further comprisingreceiving the acknowledgment mask from the transmitter.
 12. The methodof claim 6, the transmitting an acknowledgment message comprising:applying a non-zero gain to an acknowledgment signal comprising a Walshfunction associated with the acknowledgment message; and combining theacknowledgment signal with a traffic signal for transmission.
 13. Themethod of claim 6, the commencing reception of the first frame beingreceived on a first channel, the transmitting the acknowledgment messagebeing done on a first acknowledgment channel, the method furthercomprising: commencing reception of a second frame on a second channelfrom the transmitter; attempting to decode the second frame prior toreceiving the entire second frame; determining a successful frame decodebased on a result of the attempting to decode the second frame; andtransmitting an acknowledgment message to the transmitter based ondetermining the successful frame decode for the second frame, whereinthe acknowledgment message is operable to cease transmission of thesecond frame.
 14. The method of claim 6, further comprising: commencingreception of a second frame from a second transmitter; attempting todecode the second frame prior to receiving the entire second frame;determining a successful decode of the second frame based on a result ofthe attempting; transmitting an acknowledgment message to the secondtransmitter based on determining the successful decode of the secondframe, wherein the acknowledgment message is operable to terminatetransmission of an untransmitted portion of the plurality of sequentialsub-segments of the second frame, the transmitting the acknowledgmentmessage to the transmitter comprising modulating at least one bit on acommon acknowledgment channel, the transmitting the acknowledgmentmessage to the second transmitter comprising modulating at least oneother bit on the same common acknowledgment channel.
 15. The method ofclaim 14, further comprising spreading the common acknowledgment channelusing a single Walsh function.
 16. The method of claim 14, the at leastone bit corresponding to the acknowledgment message transmitted to thetransmitter being time multiplexed on the same common acknowledgmentchannel with the at least one other bit corresponding to theacknowledgment message transmitted to the second transmitter.
 17. Themethod of claim 6, the transmitting an acknowledgment message comprisingmodulating a signal on a distinct Walsh code using on-off keying. 18.The method of claim 6, the transmitting an acknowledgment messagecomprising modulating at least one ACK bit of a traffic channel, the atleast one ACK bit supplanting at least one traffic bit on the trafficchannel.
 19. The method of claim 18, the position of the ACK bit in thetraffic channel varied on a per-frame basis.
 20. An apparatus for earlytermination of sequential frame transmissions over a communicationschannel, the apparatus comprising: a transmitter configured to commencetransmission of a first frame to a receiver, each frame formatted into aplurality of sequential sub-segments and sequentially transmittedwithout awaiting sub-segment acknowledgment until a successful decode ofthe first frame; a receiver module configured to receive anacknowledgment message from the receiver during the transmission of thefirst frame, the acknowledgment message transmitted at one ofpredetermined times designated by an acknowledgement mask designating aninterval having a duration of less than a complete one of the pluralityof sequential sub-segments and indicating a successful decode of thefirst frame based on an already transmitted portion of the plurality ofsequential sub-segments of the first frame; and the transmitterconfigured to cease the transmission of an untransmitted portion of theplurality of sequential sub-segments of the first frame after receivingthe acknowledgment message.
 21. The apparatus of claim 20, each frameallotted a fixed time interval for transmission, the transmitter furtherconfigured to commence transmission of a second frame after the fixedtime interval has elapsed for the first frame, the second frameimmediately following the first frame in frame sequence.
 22. Theapparatus of claim 20, the transmitter further configured to adjust atransmit power of the first frame in response to receiving a powercontrol message from the receiver.
 23. The apparatus of claim 20, eachframe formatted into a plurality of sequential sub-segments, thetransmitter configured to continuously transmit by: continuouslytransmitting sub-segments of the first frame in sequence to thereceiver.
 24. The apparatus of claim 20, each frame comprisingfractionally encoded bits interleaved over time.
 25. An apparatus forearly termination of sequential frame transmissions over acommunications channel, the apparatus comprising: a receiver configuredto commence reception of a first frame from a transmitter, each frameformatted into a plurality of sequential sub-segments and sequentiallyreceived without awaiting sub-segment acknowledgment until a successfuldecode of the first frame; a processor configured to: attempt to decodethe first frame prior to receiving the entire first frame; determine asuccessful frame decode based on a result of the attempting; and atransmitter module configured to transmit an acknowledgment message tothe transmitter based on determining the successful frame decode, theacknowledgment message transmitted at one of predetermined timesdesignated by an acknowledgement mask designating an interval having aduration of less than a complete one of the plurality of sequentialsub-segments and indicating a successful decode of the first frame basedon an already transmitted portion of the plurality of sequentialsub-segments of the first frame, wherein the acknowledgment messagecauses the transmitter to cease the transmission of an untransmittedportion of the plurality of sequential sub-segments of the first frame.26. The apparatus of claim 25, each frame allotted a fixed time intervalfor transmission, the processor further configured to: commencereceiving a second frame after the fixed time interval has elapsed forthe first frame, the second frame immediately following the first framein frame sequence.
 27. The apparatus of claim 25, the transmitter modulefurther configured to transmit a power control message to thetransmitter to adjust a transmit power of the first frame.
 28. Theapparatus of claim 25, the receiver configured to commence reception by:continuously receiving sub-segments of the first frame in sequence fromthe transmitter.
 29. The apparatus of claim 28, the transmitter modulefurther configured to transmit the acknowledgment message only at theone of the predetermined times.
 30. The apparatus of claim 25, thereceiver further configured to receive the acknowledgment mask from thetransmitter.
 31. The apparatus of claim 25, the transmitter moduleconfigured to transmit the acknowledgment message by: applying anon-zero gain to an acknowledgment signal comprising a Walsh functionassociated with the acknowledgment message; and combining theacknowledgment signal with a traffic signal for transmission.
 32. Theapparatus of claim 25, the commencing reception of the frame beingreceived on a first channel, the transmitter module further configuredto transmit the acknowledgment message on a first acknowledgmentchannel, the receiver further configured to commence reception of asecond frame on a second channel from the transmitter; the processorfurther configured to attempt to decode the second frame prior toreceiving the entire second frame, the processor further configured todetermine a successful frame decode based on a result of the attemptingto decode the second frame; and the transmitter module furtherconfigured to transmit an acknowledgment message to the transmitterbased on determining the successful frame decode for the second frame,wherein the acknowledgment message causes the transmitter to ceasetransmission of the second frame.
 33. The apparatus of claim 25, thereceiver further configured to commence reception from a secondtransmitter of a second frame; the processor further configured toattempt to decode the second frame prior to receiving the entire secondframe; the processor further configured to determine a successful decodeof the second frame based on a result of the attempting; the transmittermodule further configured to transmit an acknowledgment message to thesecond transmitter based on determining the successful decode of thesecond frame, wherein the acknowledgment message causes the transmitterto terminate transmission of an untransmitted portion of the pluralityof sequential sub-segments of the second frame, the transmitter modulefurther configured to transmit the acknowledgment message to thetransmitter by modulating at least one bit on a common acknowledgmentchannel, the transmitter module further configured to transmit theacknowledgment message to the second transmitter by modulating at leastone other bit on the same common acknowledgment channel.
 34. Theapparatus of claim 33, the transmitter module further configured tospread the common acknowledgment channel using a single Walsh function.35. The apparatus of claim 33, the at least one bit corresponding to theacknowledgment message transmitted to the transmitter being timemultiplexed on the same common acknowledgment channel with the at leastone other bit corresponding to the acknowledgment message transmitted tothe second transmitter.
 36. The apparatus of claim 25, the transmittermodule further configured to transmit an acknowledgment message bymodulating a signal on a distinct Walsh code using on-off keying. 37.The apparatus of claim 25, the transmitter module further configured totransmit an acknowledgment message by modulating at least one ACK bit ofa traffic channel, the at least one ACK bit supplanting at least onetraffic bit on the traffic channel.
 38. The apparatus of claim 37, theposition of the ACK bit in the traffic channel varied on a per-framebasis.
 39. An apparatus for early termination of frame transmissionsover a communications channel, the apparatus comprising: means forcommencing reception of a first frame from a transmitter, each frameformatted into a plurality of sequential sub-segments and sequentiallyreceived without awaiting sub-segment acknowledgment until a successfuldecode of the first frame; means for terminating transmissions of anuntransmitted portion of the plurality of sequential sub-segments fromthe transmitter prior to receiving the entire frame by transmitting anacknowledgment message to the transmitter based on determining thesuccessful frame decode, the acknowledgment message transmitted at oneof predetermined times designated by an acknowledgement mask designatingan interval having a duration of less than a complete one of theplurality of sequential sub-segments and indicating a successful decodeof the first frame based on an already transmitted portion of theplurality of sequential sub-segments of the first frame.
 40. Anapparatus for early termination of frame transmissions over acommunications channel, the apparatus comprising: means for commencingtransmission of a first frame, each frame formatted into a plurality ofsequential sub-segments and sequentially transmitted without awaitingsub-segment acknowledgment until a successful decode of the first frame;means for terminating the transmission of an untransmitted portion ofthe plurality of sequential sub-segments receiving an acknowledgmentmessage from the receiver during the transmission of the first frame,the acknowledgment message transmitted at one of predetermined timesdesignated by an acknowledgement mask designating an interval having aduration of less than a complete one of the plurality of sequentialsub-segments and indicating a successful decode of the first frame basedon an already transmitted portion of the plurality of sequentialsub-segments of the first frame based on a successful decode of the atleast one transmitted sub-segment by a receiver.
 41. A non-transitorycomputer-readable storage medium storing instructions for causing acomputer to perform early termination of frame transmissions over acommunications channel, the medium storing instructions for causing acomputer to: receive from a transmitter a first frame, each frameformatted into a plurality of sequential sub-segments and sequentiallyreceived without awaiting sub-segment acknowledgment until a successfuldecode of the first frame; attempt to decode the frame prior toreceiving the entire frame; determine a successful frame decode based ona result of the attempting; and transmit an acknowledgment message tothe transmitter based on determining the successful frame decode, theacknowledgment message transmitted at one of predetermined timesdesignated by an acknowledgement mask designating an interval having aduration of less than a complete one of the plurality of sequentialsub-segments and indicating a successful decode of the first frame basedon an already transmitted portion of the plurality of sequentialsub-segments of the first frame, wherein the acknowledgment message isoperable to terminate transmission of an untransmitted portion of theplurality of sequential sub-segments of the frame.
 42. A non-transitorycomputer-readable storage medium storing instructions for causing acomputer to perform for early termination of frame transmissions over acommunications channel, each frame being allotted a fixed time intervalfor transmission, the medium storing instructions for causing a computerto: commence transmission of a first frame, each frame formatted into aplurality of sequential sub-segments and sequentially transmittedwithout awaiting sub-segment acknowledgment until a successful decode ofthe first frame; receive an acknowledgment message from a receiverduring the transmitting the first frame, the acknowledgment messagetransmitted at one of predetermined times designated by anacknowledgement mask designating an interval having a duration of lessthan a complete one of the plurality of sequential sub-segments andindicating a successful decode of the first frame based on an alreadytransmitted portion of the plurality of sequential sub-segments of thefirst frame; cease transmission of an untransmitted portion of theplurality of sequential sub-segments of the first frame after receivingthe acknowledgment message; and start to transmit a second frame afterthe fixed time interval has elapsed for the first frame.
 43. A methodfor early termination of sequential frame transmissions over acommunications channel, the method comprising: commencing transmissionof a first frame to at least one receiver, each frame formatted into aplurality of sequential sub-segments and sequentially transmittedwithout awaiting sub-segment acknowledgment until a successful decode ofthe first frame; receiving at least one acknowledgment message from theat least one receiver during the transmitting the first frame, theacknowledgment message transmitted at one of predetermined timesdesignated by an acknowledgement mask designating an interval having aduration of less than a complete one of the plurality of sequentialsub-segments and indicating a successful decode of the first frame basedon an already transmitted portion of the plurality of sequentialsub-segments of the first frame; and ceasing transmission of anuntransmitted portion of the plurality of sequential sub-segments of thefirst frame after receiving the first of the at least one acknowledgmentmessage.
 44. The method of claim 43, the at least one receivercomprising a first receiver and a second receiver, the receiving the atleast one acknowledgment message from the at least one receivercomprising receiving an acknowledgment message from the first receiverand an acknowledgment message from the second receiver.
 45. A method forearly termination of sequential frame transmissions over acommunications channel, the method comprising: commencing reception of afirst frame from at least one transmitter, each frame formatted into aplurality of sequential sub-segments and sequentially received withoutawaiting sub-segment acknowledgment until a successful decode of thefirst frame; attempting to decode the first frame prior to receiving theentire first frame; determining a successful frame decode based on aresult of the attempting; and transmitting an acknowledgment messagebased on determining the successful frame decode, the acknowledgmentmessage transmitted at one of predetermined times designated by anacknowledgement mask designating an interval having a duration of lessthan a complete one of the plurality of sequential sub-segments andindicating a successful decode of the first frame based on an alreadytransmitted portion of the plurality of sequential sub-segments of thefirst frame, wherein the acknowledgment message causes each of the atleast one transmitter to cease transmission of an untransmitted portionof the plurality of sequential sub-segments of the first frame by eachof the at least one transmitter.
 46. The method of claim 45, the atleast one transmitter comprising a first transmitter and a secondtransmitter, the transmitting the acknowledgment message comprisingtransmitting the acknowledgment message to both the first transmitterand the second transmitter.